Taking into account the requirements to reduce the costs of the available volumes and the total weight, which still prevail particularly in the field of automobile manufacture, there is a high demand for reducing the number of elements for regulating and monitoring the circulation of fluid in the complex circuits.
To the extent possible, an attempt is made in particular to integrate all of the regulating and monitoring functions into a single functional and structural unit, controlled by a single actuator, thus resulting in a single regulating node for several circuit parts of the same general circuit, for example a cooling circuit.
One additional possibility for cost reduction consists in implementing actuators that are low in cost and therefore have a simple and unsophisticated structure, for example rotary or linear actuators.
A dual problem then arises, namely the spatial connection of the different portions of the circuit at the node (bulkiness problem) and the implementation of different regulations for the different portions of the circuit while taking into account their hierarchy, their functions, and the production conditions, based on the general regulation at the level of the overall circuit.
The problems mentioned above occur in particular within the framework of the regulation, by means of a structural device or a single module, the circulation of the cooling liquid in a circuit that comprises a primary portion and three secondary portions, namely, for example, in addition to the circuit that passes through the engine block, also a loop that passes through a radiator, a loop that passes through a heater, as well as a bypass loop.
Valve units that essentially correspond to the different expectations that are expressed above are already known by the documents FR 2 906 334 and FR 2 906 335.